1. Field of the Invention
The present invention relates to a technical field of ignition plugs for internal combustion engines using gasoline as fuel. The automobile manufacturing industry and the aircraft manufacturing industry using internal combustion engines make sincere efforts to decrease noxious substances like nitrogen oxides such as nitrogen dioxide and carbon oxides such as carbon monoxide contained in the exhaust gas emitted from engines, as efforts for developing low-pollution engines.
The present invention has been achieved to meet the demand for low-pollution engines. In the double ignition type ignition plug of the present invention, a sealed cavity is formed in the insulator outside the ignition plug, and electric arc rods are provided as parts of the feeder circuit in this cavity, to face each other with a clearance of about 10 mm kept between them. A spark is discharged in this clearance, and simultaneously, the largest possible powerful electric spark is generated at the ignition port element of the ignition plug. In this structure, electric sparks are generated simultaneously at two points by one ignition plug; inside and outside a cylinder of an engine. This system allows large electric sparks to be generated for perfect combustion of fuel gas. So, the ignition plug for double ignition systems can decrease the concentration of noxious substance in the exhaust gas by more than 60% compared to the conventional ignition plug, and can enhance the output of the engine of the same type by about 25%, for greater contribution to the traffic industry and the transport industry.
On the other hand, the electric spark generator of the present invention is used in combination with a conventional ignition plug, and since it is the same as the above double ignition type ignition plug in effect and action, it relates also to the same technical field.
2. The Prior Art
The conventional ignition plug for internal combustion engines adopts a single ignition system in which an electric spark is generated in a clearance of about 1 mm in the ignition port element of the ignition plug in a cylinder of an engine, for explosion of fuel gas. The efforts made by respective manufacturers of internal combustion engines for developing low-pollution engines have been centered on the improvement of the engine itself such as the CVCC (compound vortex controlled combustion) engine with a sub combustion chamber in addition to a main combustion chamber, and the catalytic methods for decreasing noxious substances in the exhaust gas. The CVCC engine is not used any more since the burning of lean mixture lowers the engine output, hence, lowers the driving performance and quality which the tomobiles are expected to achieve. On the other hand, the catalytic methods cannot be said to be perfect due to many problems such as the dissolution of the catalyst caused by imperfect combustion of fuel gas, even though the catalytic methods are mainly pursued for the development of low-pollution engines. In addition, the improvement of the engine itself and the adoption of any catalytic method require large costs. In this situation, little efforts have been made for the improvement of the ignition plug itself which has been made in the present invention.